JP2007226248A - Display device and method of controlling touch detection unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device and a method of control a touch detection unit that can reduce power consumption associated with the operation of sensing units. <P>SOLUTION: A display device may include a display panel, a plurality of pixels that are disposed on the display panel, the plurality of sensing units that are disposed on the display panel to generate sensing signals based on a touch on the display panel, a sensing signal processor that receives the sensing signals and performs predetermined signal processes to generate sensing data, a first controller that determines, based on the sensing data from the sensing signal process, whether or not there is a touch on the sensing units and whether or not the sensing signal is in an appropriate range, and a second controller that determines a touch and touch positions on the sensing units based on the sensing data and controls the sensing signals to be in the desired range. Thus, it is normally determined whether there is a touch on the sensing unit and touch positions under the control of the first controller to perform only operation for putting the sensing signals in the appropriate range, so that unnecessary power consumption by the second controller with large power consumption is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device and a control method for a contact determination unit.

  A liquid crystal display device (LCD) as a representative display device includes two display panels each provided with a pixel electrode and a common electrode, and a liquid crystal layer having dielectric anisotropy sandwiched therebetween. The pixel electrodes are arranged in a matrix, are connected to switching elements such as thin film transistors (TFTs), and are sequentially applied with data voltages row by row. The common electrode is formed over the entire surface of the display panel and receives a common voltage. The pixel electrode, the common electrode, and the liquid crystal layer between them constitute a liquid crystal capacitor in terms of a circuit, and the liquid crystal capacitor is a basic unit constituting a pixel together with a switching element connected thereto.

  In such a liquid crystal display device, a voltage is applied to the two electrodes to generate an electric field in the liquid crystal layer, and the intensity of this electric field is adjusted to adjust the transmittance of light passing through the liquid crystal layer. Get an image. At this time, the polarity of the data voltage with respect to the common voltage is inverted for each frame, for each row, or for each pixel in order to prevent a deterioration phenomenon caused by applying a unidirectional electric field to the liquid crystal layer for a long time. .

  The touch screen panel is a device that touches a screen with a fingertip or a touch pen (touchpen, stylus) or the like to draw a character or a figure, or executes an icon to execute a command necessary for a machine such as a computer. The liquid crystal display device to which the touch screen panel is attached can sense whether or not a user's fingertip or touch pen touched the screen, and the touched position information. However, the conventional liquid crystal display device having such a touch screen panel has an increased cost due to the touch screen panel, a decrease in yield due to the addition of a process of bonding the touch screen panel on the liquid crystal display plate, There are problems such as brightness reduction and restrictions when expanding the product width.

  Therefore, in order to solve such a problem, a technique has been developed in which a sensing element including a thin film transistor or a variable capacitor is built in a display area for displaying an image of a liquid crystal display device instead of a conventional touch screen panel. When the sensing element senses a change in light or pressure applied to the screen by the user's fingertip or the like, the liquid crystal display device can obtain whether or not the user's fingertip or the like has touched the screen and contact position information.

  However, in this case, the signal from the sensing element built in the liquid crystal display device is processed to determine the presence / absence and contact position of the sensing unit, and the level of the sensing signal varies depending on the panel of the liquid crystal display device and the surrounding environment. Therefore, it is necessary to adjust the driving voltage so as to be within the usable range. For this purpose, a processor such as an ARM (advanced RISC machine) is used. On the other hand, when such a processor is used, there is a problem that power consumption increases due to access to a memory, generation of a drive clock, and the like.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a display device capable of reducing power consumption associated with operation of a sensing unit that processes a signal from a sensing element, and It is in providing the control method of a contact judgment part.

In order to achieve the above object, a display device according to the present invention includes a display panel, a plurality of pixels formed on the display panel, and a detection signal formed on the display panel based on contact with the display panel. A plurality of sensing units to be generated, a sensing signal processing unit that receives the sensing signal, performs predetermined signal processing to generate sensing data, and a contact of the sensing unit based on sensing data from the sensing signal processing unit A first control unit for determining presence / absence and whether or not the sensing signal is in an appropriate range; and determining presence / absence and contact position of the sensing unit based on the sensing data; And a contact determination unit including a second control unit that controls the control unit to exist within the contact control unit.
The second control unit is preferably configured using an ARM (advanced RISC machine) processor, and the first control unit is preferably configured with hard-wired logic.

The first control unit includes a data classifying unit that classifies the sensing data into vertical and horizontal sensing signals, a memory unit that stores the classified vertical and horizontal sensing data, and a vertical sensing signal from the memory unit. A contact state check unit that determines whether or not the sensing unit is in contact based on the sensor, and a stable state determination unit that determines whether the sense signal belongs to an appropriate range based on the sense signal from the memory unit. It is preferable.
The contact determination unit preferably further includes a register unit that stores a plurality of flag values.
The plurality of flags include a memory status flag indicating that all of the horizontal and vertical sensing signals are stored in the memory unit, a wake-up flag for controlling the operation of the second control unit, and the sensing signal It is preferable to include an unstabilized state flag indicating whether or not the sensor belongs to an appropriate range and a contact state flag indicating whether or not contact has occurred in the sensing unit.
The wake-up flag has a value of an active state when a contact is generated in the sensing unit by checking the contact state or when the sensing signal is not within an appropriate range by the stable state determining unit. Is preferred.

When the wake-up flag is in an active state, the second control unit determines whether the sensing unit is in contact with the sensing unit based on the sensing data, and determines whether the sensing signal is within an appropriate range. It is preferable to control to belong.
The non-stabilized state flag preferably has an active state value when the stable signal is not in an appropriate range by the stable state determination unit.
The unstabilized state flag may have an active state value after an enable signal is applied to the contact determination unit and power is supplied.
The contact state flag preferably has an active state value when it is determined by the contact state check that contact has occurred in the sensing unit.
The memory status flag may have an active state value when the horizontal and vertical data are all stored in the memory unit by the data classification unit.
Preferably, the contact determination unit further includes an interface unit. This interface unit is preferably an SPI (Serial Peripheral Interface).
Each of the plurality of sensing units preferably includes a variable capacitor whose capacitance changes with an external pressure, and a reference capacitor having a predetermined capacitance.

In order to achieve the above object, the control method of the contact determination unit according to the present invention determines the presence / absence of a contact and the contact position based on sensing signals generated by a plurality of sensing units by contact with the display panel, 2. A method for controlling a contact determination unit including a control unit, wherein it is determined whether an enable signal is applied from the outside, and when the enable signal is applied, a power source for operation of the contact determination unit is turned on. An initialization step of supplying, classifying the sensing signals and storing them in a memory; then, based on the sensing signals, it is determined whether or not the sensing unit is in contact and whether the sensing signals are within an appropriate range. , A control step of the first control unit for activating the wake-up flag, and a stabilizing operation for causing the sensing signal to be within an appropriate range when the value of the wake-up flag is in the active state. And having a control stage of the second control unit for performing the operation of determining the presence and the contact position of the contact of the detection unit.
Preferably, the initialization step further includes a step of activating values of the wake-up flag and the non-stabilized state flag so that the stabilizing operation by the second controller is performed.

  The control step of the first control unit includes classifying the sensing signals into vertical and horizontal sensing signals, storing them in a memory, and switching the value of a memory status flag to an active state after the storage is completed, and the wake-up flag includes Transitioning to the operation of the second controller if active, determining if the sensing signal is within an appropriate range if the wake-up flag is not active, and detecting the sensing Determining whether contact has occurred in the sensing unit if the signal is within a proper range; performing a classification operation of the sensing signal if contact has not occurred in the sensing unit; When contact occurs, the wake-up flag and the contact state flag are switched to an active state, and when the sensing signal is not within an appropriate range, A step of switching the Pufuraggu and unstabilized state flag to the active state, it is preferable to include a.

  The control step of the second controller includes determining whether the memory state flag is active, and if the memory state flag is active, the unstabilized state flag is active. Determining whether or not the unstabilized state flag is in an active state, and determining whether the sensing signal is within an appropriate range after the memory state flag is deactivated; When the sensing signal is not within the proper range, outputting a control signal for changing the level of the sensing signal; and when the sensing signal is within the proper range, the wake-up flag is deactivated When the non-stabilized state flag is in the active state, determining whether the contact state flag is in the active state, and the contact state flag If the contact state flag is in the active state, and the contact state flag is in the active state, the presence / absence of the contact and the contact position are determined to determine whether the contact state is in the contact state. Generating contact information; if contact occurs in the sensing unit; transitioning to determining whether the memory status flag is active; and if no contact occurs in the sensing unit; Preferably the step of shutting off the power by setting the flag in an inactive state.

  According to the control method of the display device and the contact determination unit of the present invention, when determining the presence / absence and contact position of the sensing unit, a large amount of power is consumed only during the output voltage stabilization operation when not in contact. The second control unit, which is a processor such as ARM, is activated, and at other times, the power is cut off to maintain the power saving state. As a result, the power consumption generated in the second control unit is reduced, and as a result, the power consumption of the display device incorporating the sensing unit is also reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, with reference to the accompanying drawings, a person having ordinary knowledge in the technical field to which the invention belongs will easily implement the best mode for carrying out a display device and a method for controlling a contact determination unit according to the invention. It will be described in detail so that it can be. In the drawings, the thickness is enlarged to clearly show various layers and regions. Similar parts are denoted by the same reference numerals throughout the specification. When a part such as a layer, a film, a region, or a plate is “on top” of another part, this is not limited to the case of “on top” of the other part. Including some cases. Conversely, when a part is “just above” another part, this means that there is no other part in the middle.

A specific example applied to a liquid crystal display device as an embodiment of the display device according to the present invention will be described in detail with reference to FIGS.
FIG. 1 is a block diagram of a liquid crystal display device according to an embodiment of the present invention, which is shown in terms of pixels. FIG. 2 is an equivalent circuit diagram for one pixel of the liquid crystal display device according to the embodiment of the present invention. FIG. 3 is a block diagram of a liquid crystal display device according to an embodiment of the present invention, which is shown from the perspective of a sensing unit. FIG. 4 is an equivalent circuit diagram of one sensing unit of the liquid crystal display device according to the embodiment of the present invention. FIG. 5 is a schematic view of a liquid crystal display device according to an embodiment of the present invention. FIG. 6 is an equivalent circuit diagram of a plurality of sensing units connected to one sensing data line in the liquid crystal display device according to the embodiment of the present invention.

  As shown in FIGS. 1 and 3, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel assembly 300, an image scanning unit 400 connected thereto, an image data driving unit 500, and a sensing signal processing unit 800. , A gradation voltage generating unit 550 connected to the image data driving unit 500, a contact determining unit 700 connected to the sensing signal processing unit 800, and a signal control unit 600 for controlling them.

Referring to FIG. 1 to FIG. 4, the liquid crystal panel assembly 300 is connected to a plurality of display signal lines (G ₁ -G _n , D ₁ -D _m ) and arranged substantially in a matrix. that a plurality of pixels (PX), a plurality of sensing signal lines _{(SY 1 -SY N, SX 1} -SX M, RL) and a plurality of sensing units arranged substantially in a matrix connected thereto (SU), a plurality of reset signal input section connected to one end of the sensing signal lines _{(SY1-SY N, SX 1} -SX M) (INI), each sensing signal line _{(SY 1 -SY N, SX 1} -SX M) A plurality of sensing signal output units (SOUT) connected to the other end of the sensor and a plurality of output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) connected to each sensing signal output unit (SOUT) Including.

  On the other hand, as shown in FIGS. 2 and 5, the liquid crystal panel assembly 300 includes a thin film transistor panel 100 and a common electrode panel 200 facing each other, a liquid crystal layer 3 sandwiched therebetween, and the thin film transistor panel 100 and An interval material (not shown) that compresses and deforms to some extent is generated between the two display panels of the common electrode display panel 200.

The display signal lines (G ₁ -G _n , D ₁ -D _m ) are a plurality of image scanning lines (G ₁ -G _n ) that transmit image scanning signals and image data lines (D ₁ ) that transmit image data signals. includes -D _m) and, sensing the signal line _{(SY 1 -SY N, SX 1} -SX M, RL) , a plurality of horizontal sensing data lines for transmitting sensor data signals _(SY 1 -SY _N) and a plurality of It includes a vertical sensing data line (SX ₁ -SX _M ) and a plurality of reference voltage lines (RL) having a high level and a low level and transmitting a reference voltage that swings between the high level and the low level in a certain cycle. The reference voltage line (RL) may be omitted as necessary.

The image scanning lines (G ₁ -G _n ) and the horizontal sensing data lines (SY ₁ -SY _N ) extend substantially in the row direction and are substantially parallel to each other, and the image data lines (D ₁ -D _m ) and the vertical sensing data lines The data lines (SX ₁ -SX _M ) extend substantially in the column direction and are substantially parallel to each other. The reference voltage line (RL) extends in the row or column direction.

Each pixel (PX) includes a switching element (Q) connected to the display signal lines (G ₁ -G _n , D ₁ -D _m ), a liquid crystal capacitor (Clc) and a storage capacitor (Cst) connected thereto. including. The storage capacitor (Cst) may be omitted as necessary.

Switching element (Q) is a three terminal element such as a thin film transistor provided in the TFT array panel 100, a control terminal is connected to the image scanning lines (G 1 _{-G n),} the input terminal image The data line (D ₁ -D _m ) is connected, and the output terminal is connected to the liquid crystal capacitor (Clc) and the storage capacitor (Cst). Here, the thin film transistor is made of amorphous silicon or polycrystalline silicon.

  The liquid crystal capacitor (Clc) has the pixel electrode 191 of the thin film transistor array panel 100 and the common electrode 270 of the common electrode panel 200 as two terminals, and the liquid crystal layer 3 between the two electrodes of the pixel electrode 191 and the common electrode 270 is Functions as a dielectric. The pixel electrode 191 is connected to the switching element (Q), and the common electrode 270 is formed on the entire surface of the common electrode panel 200 and receives a common voltage (Vcom). Unlike FIG. 2, the common electrode 270 may be provided on the thin film transistor array panel 100. In this case, at least one of the two electrodes 191 and 270 may be formed in a line shape or a rod shape. The common voltage (Vcom) is a direct current (DC) voltage that is a constant voltage of a predetermined level, and can have a voltage near 0V.

  The storage capacitor (Cst) serving as an auxiliary function of the liquid crystal capacitor (Clc) is configured such that a separate signal line (not shown) provided in the thin film transistor array panel 100 and a pixel electrode 191 overlap with each other with an insulator interposed therebetween. A predetermined voltage such as a common voltage (Vcom) is applied to the separate signal lines. On the other hand, the storage capacitor (Cst) may be configured such that the pixel electrode 191 overlaps with the preceding image scanning line immediately above through the insulator.

  In order to realize color display, each pixel (PX) displays one of the basic colors uniquely (space division), or each pixel (PX) displays the basic color alternately according to time. By performing (time division), a desired hue is recognized by the spatial and temporal actions of these basic colors. Examples of basic colors include three primary colors such as red, green, and blue. FIG. 2 is an example of space division, and each pixel (PX) is provided with a color filter 230 indicating one of the basic colors in the region of the common electrode panel 200 corresponding to the pixel electrode 191. Unlike FIG. 2, the color filter 230 may be formed on or below the pixel electrode 191 of the thin film transistor array panel 100. At least one polarizer (not shown) that polarizes light is attached to the outer surface of the liquid crystal panel assembly 300.

As shown in FIG. 4, the sensing unit (SU) includes a variable capacitor (Cv) connected to a horizontal or vertical sensing data line (hereinafter referred to as a sensing data line) indicated by a symbol SL, and a sensing data line (SL). ) And a reference voltage line (RL), and a reference capacitor (Cp).
The reference capacitor Cp is configured by overlapping a reference voltage line RL and a sensing data line SL in the thin film transistor array panel 100 with an insulator (not shown) interposed therebetween.

  In the variable capacitor (Cv), the sensing data line (SL) of the thin film transistor array panel 100 and the common electrode 270 of the common electrode panel 200 have two terminals, and the liquid crystal layer 3 between the two terminals functions as a dielectric. The value of the capacitance of the variable capacitor (Cv) is changed by an external stimulus such as a user touch applied to the liquid crystal panel assembly 300. Such external stimulus has pressure, and when pressure is applied to the common electrode panel 200, the spacing member is compressed and deformed, the distance between the two terminals is changed, and the capacitance of the variable capacitor (Cv) is changed. . When the capacitance changes, the magnitude of the node voltage (Vn) between the reference capacitor (Cp) and the variable capacitor (Cv) that depends on the magnitude of the capacitance changes. The node voltage (Vn) is a sensing data signal that flows through the sensing data line (SL), and based on this, the presence or absence of contact can be determined. At this time, the distance between both terminals of the reference capacitor (Cp) is constant and has a substantially constant capacitance.

  As a result, the sensed data signal can always have a voltage level within a certain range, and as a result, the presence / absence of contact and the contact position can be easily determined.

The sensing unit (SU) is disposed between two adjacent pixels (PX). Horizontal and vertical sensing data lines _{(SY 1 -SY N, SX 1} -SX M) are respectively connected to, the density of the pair of sensing units in which they are disposed adjacent to the region intersecting (SU), e.g. , And can be about ¼ of the dot density. Here, for example, one dot is arranged side by side and includes three pixels (PX) that display three primary colors such as red, green, and blue, displays one hue, and resolution of the liquid crystal display device Is the basic unit. On the other hand, one dot may be composed of four or more pixels (PX). In this case, each pixel (PX) can display one of three primary colors and white.

  As an example where the density of the pair of sensing units (SU) is ¼ of the dot density, the horizontal and vertical resolutions of the pair of sensing units (SU) are respectively ½ of the horizontal and vertical resolutions of the liquid crystal display device. There are cases. In that case, there may be a pixel row and a pixel column without a sensing unit (SU).

  Even if the sensing unit (SU) density and the dot density are matched to this level, such a liquid crystal display device can be applied in a highly accurate application field such as character recognition. Of course, the resolution of the sensing unit (SU) may be higher or lower as required. As described above, according to the sensing unit (SU) according to the embodiment of the present invention, since the space occupied by the sensing unit (SU) and the sensing data line (SL) is relatively small, the aperture ratio of the pixel (PX) is reduced. It can be minimized.

As shown in FIG. 6, the plurality of reset signal input units (INI) all have the same structure, and each have a reset transistor (Qr). The reset transistor (Qr) is a three-terminal element of a thin film transistor, its control terminal is connected to the reset control signal (RST), its input terminal is connected to the reset voltage (Vr), and its output terminal is sensing data line (SL) is connected to the _(SX 1 -SX _M or _SY 1 -SY _N in FIG. 3). The reset transistor (Qr) is located in the peripheral region (P2) of the liquid crystal panel assembly 300 where no pixels are arranged, and supplies a reset voltage (Vr) to the sensing data line (SL) by a reset control signal (RST). To do.

  Similarly, the plurality of sensing signal output units (SOUT) have the same structure and each have an output transistor (Qs). The output transistor (Qs) is also a three-terminal element of a thin film transistor, its control terminal is connected to the sensing data line (SL), its input terminal is connected to the input voltage (Vs), and its output terminal is the output data line. (OL). The output transistor (Qs) is also located in the peripheral area (P2) of the liquid crystal panel assembly 300, and generates an output signal based on a sensing data signal that flows through the sensing data line (SL). The output signal has an output current. On the other hand, the output transistor (Qs) can also generate a voltage as an output signal.

  The reset transistor (Qr) and the output transistor (Qs), which are thin film transistors, are formed together with the switching element (Q).

Output data lines _{(OY 1 -OY N, OX 1} -OX M) , each through the sensing signal output part (SOUT) horizontal and vertical sensing data lines _{(SY 1 -SY N, SX 1} -SX M) to It includes a plurality of horizontal and vertical output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) that are connected. The output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) are connected to the sensing signal processing unit 800 and transmit an output signal from the sensing signal output unit (SOUT) to the sensing signal processing unit 800. The horizontal and vertical output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) extend substantially in the column direction and are substantially parallel to each other.

  Referring back to FIGS. 1 and 3, the gray voltage generator 550 generates two sets of gray voltages (or reference gray voltages) related to the transmittance of the pixels. One set has a positive value for the common voltage (Vcom) and the other set has a negative value.

The image scanning unit 400 is connected to the image scanning lines (G ₁ -G _n ) of the liquid crystal panel assembly 300 to turn on the switching element (Q), and to turn off the gate off voltage (Voff). An image scanning signal composed of the above combination is applied to the image scanning lines (G ₁ -G _n ).

The image data driver 500 is connected to the image data lines (D ₁ -D _m ) of the liquid crystal panel assembly 300, selects the gradation voltage from the gradation voltage generator 550, and uses this as the image data signal. Applied to the image data lines (D ₁ -D _m ). However, the gradation voltage generation unit 550 may not provide all voltages for all gradations, but may provide only a predetermined number of reference gradation voltages. In this case, the image data driving unit 500 may provide the reference data. The gradation voltage is divided to generate gradation voltages for all gradations, and an image data signal is selected from among the gradation voltages.

The sensing signal processing unit 800 includes a plurality of amplifying units 810 connected to output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) of the liquid crystal panel assembly 300.
The plurality of amplification units 810 shown in FIG. 6 all have the same structure, and each amplification unit 810 includes an amplifier (AP), a capacitor (Cf), and a switch (SW). The amplifier (AP) has an inverting terminal (−), a non-inverting terminal (+), and an output terminal. The inverting terminal (−) is connected to the output data line (OL), and the inverting terminal (−) A capacitor (Cf) and a switch (SW) are connected to the output terminal, and a non-inverting terminal (+) is connected to the reference voltage (Va). The amplifier (AP) and the capacitor (Cf) are current integrators, and integrate the output current from the output transistor (Qs) for a predetermined time to generate a sensing signal (Vo).

  Therefore, the sensing signal processing unit 800 converts the analog sensing signal (Vo) from the amplifying unit 810 into a digital signal using an analog-digital converter (not shown) and generates a digital sensing signal (DSN). To do.

  The contact determination unit 700 receives the digital detection signal (DSN) from the detection signal processing unit 800, performs predetermined calculation processing, determines the presence / absence of contact and the contact position, and then transmits contact information (INF) to the external device. . The contact determination unit 700 can monitor the operating state of the sensing unit (SU) based on the digital sensing signal (DSN) and control a signal applied thereto. The contact determination unit 700 will be described in detail later.

The signal control unit 600 controls operations of the image scanning unit 400, the image data driving unit 500, the gradation voltage generation unit 550, the sensing signal processing unit 800, and the like.
Each of the driving devices of the image scanning unit 400, the image data driving unit 500, the gradation voltage generating unit 550, the signal control unit 600, the contact determination unit 700, and the sensing signal processing unit 800 is at least one integrated circuit chip. It is mounted directly on the LCD panel assembly 300 in the form, or mounted on the flexible printed circuit film (not shown) and attached to the LCD panel assembly 300 in the form of a TCP (tape carrier package). Or can be mounted on a separate printed circuit board (not shown). Unlike this, these drive devices 400,500,550,600,700,800 signal lines _{(G 1 -G n, D 1} -D m, SY 1 -SY N, SX 1 -SX M, OY 1 - OY _N , OX ₁ -OX _M , RL), a thin film transistor (Q), and the like may be integrated in the liquid crystal panel assembly 300.

As shown in FIG. 5, the liquid crystal panel assembly 300 is divided into a display area (P1), a peripheral area (P2), and an exposed area (P3). Pixel in the display region (P1) (PX), the sensing unit (SU), and each of the signal lines _{(G 1 -G n, D 1} -D m, SY 1 -SY N, SX 1 -SX M, OY 1 - _{OY N, OX 1 -OX M,} RL) most are located. The common electrode panel 200 has a light shielding member (not shown) such as a black matrix. The light shielding member covers most of the peripheral area (P2) and blocks light from the outside. The common electrode panel 200 is smaller than the thin film transistor panel 100, and a part of the thin film transistor panel 100 is exposed to form an exposed region (P3). A single chip 610 is mounted on the exposed region (P3). Then, the FPC board 620 is attached.

  The single chip 610 is a driving device for driving the liquid crystal display device, that is, the image scanning unit 400, the image data driving unit 500, the gradation voltage generating unit 550, the signal control unit 600, the contact determination unit 700, and the sensing signal. A processing unit 800 is included. By mounting such driving devices 400, 500, 550, 600, 700, and 800 in a single chip 610, a mounting area can be reduced and power consumption can also be reduced. Of course, if necessary, at least one of them or at least one circuit element forming them may be located outside the single chip 610.

The image signal lines (G ₁ -G _n , D ₁ -D _m ) and the sensing data lines (SY ₁ -SY _N , SX ₁ -SX _M ) extend to the exposure region (P3) and correspond to the driving device 400. , 500, 800.

  The FPC board 620 receives a signal from an external device and transmits it to the single chip 610 or the liquid crystal panel assembly 300, and usually has a connector (not shown) at an end to facilitate connection with the external device. Consists of.

Next, the display operation and sensing operation of such a liquid crystal display device will be described in more detail.
The signal controller 600 receives an input image signal (R, G, B) and an input control signal for controlling the display from an external device (not shown). The input image signal (R, G, B) includes luminance information of each pixel (PX), and the luminance is a predetermined number, for example, 1024 (= 2 ¹⁰ ), 256 (= 2 ⁸ ), or 64 (= It has 2 ⁶ ) grays. Examples of the input control signal include a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a main clock (MCLK), and a data enable signal (DE).

  The signal control unit 600 converts the input image signals (R, G, B) into operating conditions of the liquid crystal panel assembly 300 and the image data driving unit 500 based on the input image signals (R, G, B) and the input control signals. The image scanning control signal (CONT1), the image data control signal (CONT2), the sensing data control signal (CONT3) and the like are generated appropriately, and then the image scanning control signal (CONT1) is generated. The image data control signal (CONT2) and the processed digital image signal (DAT) are sent to the image data driver 500, and the sense data control signal (CONT3) is sent to the sense signal processor 800.

  The image scanning control signal (CONT1) includes a scanning start signal (STV) for instructing the start of scanning and at least one clock signal for controlling the output of the gate-on voltage (Von). Further, the image scanning control signal (CONT1) may further include an output enable signal (OE) that limits the duration of the gate-on voltage (Von).

Image data control signal (CONT2) is a digital image signal (DAT) one pixel row image data horizontal synchronization start signal for informing the start of transmission of the of the (STH), the image data to the image data lines _(D 1 -D _m) A load signal (LOAD) and a data clock signal (HCLK) instructing application of the signal are included. The image data control signal (CONT2) is an inverted signal that inverts the voltage polarity of the image data signal with respect to the common voltage (Vcom) (hereinafter, the voltage polarity of the image data signal with respect to the common voltage is abbreviated as the polarity of the image data signal). (RVS) may further be included.

In response to the image data control signal (CONT2) from the signal control unit 600, the image data driving unit 500 receives the digital image signal (DAT) for the pixel (PX) in one pixel row and corresponds to each digital image signal (DAT). By selecting a gradation voltage to be applied, the digital image signal (DAT) is switched to an analog image data signal, and then applied to the image data line (D ₁ -D _m ).

The image scanning unit 400 applies a gate-on voltage (Von) to the image scanning line (G ₁ -G _n ) in response to an image scanning control signal (CONT 1) from the signal control unit 600, and this image scanning line (G ₁ -G _n). ) Is turned on. Then, the image data signal applied to the image data line (D ₁ -D _m ) is applied to the pixel (PX) through the switching element (Q) that is turned on.

  The difference between the voltage of the image data signal applied to the pixel (PX) and the common voltage (Vcom) appears as the charging voltage of the liquid crystal capacitor (Clc), that is, the pixel voltage. The arrangement of the liquid crystal molecules differs depending on the magnitude of the pixel voltage, and this changes the polarization of light passing through the liquid crystal layer 3. Such a change in polarization appears as a change in light transmittance by the polarizer attached to the liquid crystal panel assembly 300, and a desired image can be displayed through the change.

By repeating this process in units of one horizontal period (also referred to as 1H, which is the same as one period of the horizontal synchronization signal Hsync and the data enable signal DE), the entire image scanning line (G ₁ -G _n ) is used. Then, a gate-on voltage (Von) is sequentially applied, and an image data signal is applied to all the pixels (PX) to display an image of one frame.

  When one frame is completed, the next frame is started, and the inversion applied to the image data driver 500 so that the polarity of the image data signal applied to each pixel (PX) is opposite to the polarity in the previous frame. The state of the signal (RVS) is controlled (frame inversion). At this time, even within one frame, the polarity of the image data signal flowing through one image data line changes (row inversion, dot inversion) due to the characteristics of the inversion signal (RVS), or image data applied to one pixel row The polarities of the signals can also be different from each other (column inversion, dot inversion).

The sensing signal processing unit 800 generates output data lines (OY ₁ -OY _N , OX ₁ -OX _M ) in a porch section between frames once per frame by a sensing data control signal (CONT3). ) Is read, and the sensing operation is preferably performed in the front porch period ahead of the vertical synchronization signal (Vsync). In the pouch section, the sensed data signal is less affected by the drive signals from the image scanning unit 400 and the image data driving unit 500, so the reliability of the sensed data signal is improved. However, such a reading operation is not necessarily performed every frame, and may be performed once every a plurality of frames as necessary. Further, the reading operation may be performed twice or more in the pouch section, and the reading operation may be performed at least once in the frame.

With reference to FIG. 6, the reading operation of the sensed data signal will be described in detail.
The common voltage (Vcom) has a high level and a low level, and swings between the high level and the low level every 1H.

  The reset control signal (RST) has a turn-on voltage for turning on the reset transistor (Qr) and a turn-off voltage for turning off the reset transistor (Qr). A gate-on voltage (Von) can be used as the turn-on voltage, and a gate-off voltage (Voff) can be used as the turn-off voltage, and other voltages can also be used. The turn-on voltage of the reset control signal (RST) is applied when the common voltage (Vcom) is high level.

  When the turn-on voltage is applied to the reset transistor (Qr), the reset transistor (Qr) is turned on, and the reset voltage (Vr) applied to the input terminal is applied to the sensing data line (SL). ) Initializes the sensing data line (SL). On the other hand, when the operation is started and the reference voltage (Va) is applied to the amplification unit 810, the capacitor (Cf) of the amplification unit 810 is charged with this reference voltage (Va), so that the output of the amplifier (AP) The magnitude of the voltage (Vo) is equal to the reference voltage (Va).

  When the reset control signal (RST) becomes the turn-off voltage (Voff), the sensing data line (SL) enters a floating state, and the capacitance of the variable capacitor (Cv) changes depending on whether or not the sensing unit (SU) is touched. Based on the fluctuation of the common voltage (Vcom), the voltage applied to the control terminal of the output transistor (Qs) changes. Due to such a voltage change, the current of the sensing data signal flowing through the output transistor (Qs) varies.

  On the other hand, after the reset control signal (RST) changes to the gate-off voltage (Voff), the switching signal (Vsw) is applied to the switch (SW) to discharge the voltage charged in the capacitor (Cf).

  Thereafter, when a predetermined time elapses, the sensing signal processing unit 800 reads the sensing signal (Vo). At this time, it is preferable that the time for reading the sensing signal (Vo) is set within 1H after the reset control signal (RST) becomes the turn-off voltage (Voff). That is, it is preferable to read the sensing signal (Vo) before the common voltage (Vcom) changes to high level again. This is because the sensing signal (Vo) also changes due to the level change of the common voltage (Vcom).

  Since the sensing data signal varies with the reset voltage (Vr) as a reference, the sensing data signal can always have a voltage level within a certain range, and through this, the presence / absence of contact and the contact position can be easily determined.

  The turn-on voltage of the reset control signal (RST) can be applied when the common voltage (Vcom) is at a low level. At this time, after the common voltage (Vcom) changes to a high level, the sensing signal ( Read Vo). It is also possible to synchronize the reset control signal (RST) with the image scanning signal applied to the last image scanning line (Gn).

  As described above, after the analog sensing data signal is read by using each amplification unit 810, the sensing signal processing unit 800 converts the sensing signal (Vo) to generate a digital sensing signal (DSN), and the touch determination unit. To 700.

  The contact determination unit 700 receives the digital sensing signal (DSN), performs appropriate calculation processing, detects the presence / absence of the contact and the contact position, and transfers this to the external device. The external device transmits image signals (R, G, B) based on this to the liquid crystal display device, and displays a screen or menu selected by the user or the like.

The operation of the contact determination unit 700 will be described in detail with reference to FIGS.
FIG. 7 is a block diagram of the contact determination unit according to an embodiment of the present invention, and FIG. 8 is a flowchart illustrating the operation of the contact determination unit illustrated in FIG. FIG. 9 is a timing chart showing the operation of the contact determination unit shown in FIG.

  As shown in FIG. 7, the contact determination unit 700 according to an embodiment of the present invention includes first and second control units 710 and 720, a register unit 730, memories 740 and 750, and an interface unit 760.

  The first control unit 710 includes a data classification unit 711, a memory 712, a contact state check unit 713, and a stable state determination unit 714, which are configured with hard wire logic that consumes less power. The first controller 710 may further include an initialization unit (not shown) that controls the initial operation of the contact determination unit 700.

The data classifying unit 711 reads the digital sensing signal (DSN) from the sensing signal processing unit 800 and separates it into a vertical sensing signal and a lateral sensing signal, and then transmits them to the memory 712 for storage in the memory 712.
The contact state check unit 713 determines whether the contact operation of the sensing unit is performed based on one of the vertical sensing signal and the vertical sensing signal, for example, the vertical sensing signal.

  The stable state determination unit 714 determines whether or not the detection signal output from the detection unit (SU) is within an appropriate range. The stable state determination unit 714 determines whether the output level of the detection signal (Vo) is maintained in an appropriate range, for example, about 0.6V to 0.8V in a state where the detection unit (SU) is not touched. It is possible to determine whether or not the value of Vo) is within a normal range.

The second control unit 720 is a control unit using a processor such as ARM, and determines whether or not the sensing unit (SU) is in contact and the contact position. When the output state of the sensing signal is outside the appropriate range, By adjusting the reset voltage (Vr) or the like, the value of the sensing signal is made to be within an appropriate range.
The register unit 730 stores a flag value for notifying the operation state of each device.

  The memory 740 is a flash memory and stores an operation program for operating the second controller 720. The memory 750 is a data memory that stores horizontal and vertical sensing signals and various data necessary for operation.

  The interface unit 760 can be configured with an SPI (serial peripheral interface) or the like, sends contact information (INF), a control signal (CS), etc. to an external device, and receives input of necessary data and control signals from the outside. .

A control operation of the contact determination unit 700 having such a structure will be described with reference to FIG.
As shown in FIG. 8, the control operation of the contact determination unit 700 is performed in an initialization routine (step S10), a control routine of the first control unit 710 (step S20), and a control routine of the second control unit 720 (step S30). Divided.

  First, when the operation is started, an initialization unit (not shown) determines whether a chip enable signal is applied to the contact determination unit 700 from the outside such as the signal control unit 600 (step S11). . When the chip enable signal is applied, the initialization unit supplies power for the operation of the contact determination unit 700 (step S12), and sets the value of the wake-up flag (WU) and the value of the unstabilized state flag (UNS). 1 (step S13, step S14). The values of these flags (WU, UNS) are stored in the register unit 730.

  The wake-up flag (WU) is a flag for controlling whether or not the second control unit 720 operates. When the value is 1, the second control unit 720 is turned on to perform a predetermined operation. When the value is 0, the second controller 720 maintains a power saving state in which no power is supplied.

  The unstabilized state flag (UNS) is a flag indicating whether or not the value of the sensing signal (Vo) is within an appropriate range. When the value is 1, the value of the sensing signal is within the appropriate range. Is not present, and when the value is 0, it indicates that the value of the sensing signal is within an appropriate range.

  In order to determine whether the sensing unit (SU) is accurately touched, the value of the sensing signal needs to be within an appropriate range. Accordingly, when power is supplied and the operation starts, the values of the wake-up flag (WU) and the unstabilized state flag (UNS) are set to 1 in steps S13 and S14, and before the operation of the sensing unit (SU) is performed. In addition, the second control unit 720 adjusts the reset voltage (Vr) and the like so that the value of the sensing signal is within an appropriate range. In this state, the operations of the first and second control units 710 and 720 are performed. First, the operation of the first control unit 710 will be described.

  After the value of the wake-up flag (WU) is set to 1 in step S13, the data classification unit 711 of the first control unit 710 receives the digital detection signal (DSN) input through the interface unit 760, and receives the horizontal detection signal. Are stored in the memory 712 (step S21), and then the value of the memory status flag (Mem) is stored as 1 (step S22). The memory status flag (Mem) is a flag indicating that the horizontal and vertical sensing signals are all stored in the memory 712. If the value is 1, the horizontal and vertical sensing signals corresponding to the memory 712 are stored. This means that the sensing signal stored in the memory 712 can be used by the second control unit 720. Accordingly, similarly, this flag value is also stored in the register unit 730.

  Next, the first controller 710 determines whether or not the value of the wake-up flag (WU) is 1 (step S23).

  In steps S13 and S14, the values of the wake-up flag (WU) and the unstabilized state flag (UNS) are set for the operation of adjusting the sensing signal of the sensing unit (SU) to be within the appropriate range at the initial stage of the operation. 1 and the wake-up flag (WU) and the unstabilized flag (UNS) are in the activated state. Therefore, at the time of the first operation, the control unit moves to the control routine (step S30) of the second control unit 720 in step S23, executes steps S31 to S39, and adjusts the reset voltage (Vr) and the like, thereby detecting the sensing unit (SU). The control signal is controlled to be within an appropriate range. The operation of the second control unit 720 will be described in detail later.

  However, when the initial sensing signal level adjustment operation is completed by such an initial operation and the value of the wake-up flag (WU) is 0 in step S23, the process moves from step S23 to step S24. Therefore, the stable state determination unit 714 of the first control unit 710 sets the value of the unstabilized state flag (UNS) to 0, and the contact state check unit 713 sets the value of the contact state flag (TE) to 0. (Step S24), and thereafter, the values of the flags (UNS, TE) are initialized to 0 and set to an inactive state for the stable state determination operation and the presence / absence determination operation of the sensing signal.

  Here, the contact state flag (TE) is a flag indicating whether or not a contact of the sensing unit (SU) has occurred. When the value is 1, the contact of the sensing unit (SU) has occurred. When the value is 0, it indicates that the touch of the sensing unit (SU) does not occur. Similarly, this value is also stored in the register unit 730. As described above, the presence / absence of contact is determined by the vertical sensing signal.

  Next, the stable state determination unit 714 performs a stable state determination operation to determine whether the value of the sensing signal applied from the interface unit 760 is within an appropriate range, and determines the output range of the sensing signal ( Step S25, Step S26).

  When the sensing signal does not exist within the appropriate range, the stable state determination unit 714 sets the values of the wake-up flag (WU) and the unstabilized flag (UNS) to 1 (step S27), and the second control unit 720 Control proceeds to the control routine (step S30) so that the reset voltage (Vr) or the like is adjusted to perform a stabilizing operation so that the sensing signal is within the appropriate range.

  When the detection signal is within the appropriate range, the contact state check unit 713 determines whether or not the detection unit (SU) is in contact with the horizontal detection signal stored in the memory 712 (steps S28 and S29).

  When contact of the sensing unit (SU) occurs, the contact state check unit 713 sets the values of the wake-up flag (WU) and the contact state flag (TE) to 1 (step S201), and the second control unit 720 It moves to a control routine (step S30) so that the operation of determining the presence / absence of contact of the sensing unit (SU) and the contact position is performed.

Next, the control routine (step S30) of the second control unit 720 will be described.
In the standby state (step S31), the second controller 720 determines the value of the memory state flag (Mem) at a predetermined cycle (step S32). Therefore, when the memory status flag (Mem) is 0, it is determined that the operation of the data classification unit 711 is not completed, and the second control unit 720 moves to the standby state (step S31).

  However, when the memory status flag (Mem) is 1, since the classification of the input vertical and horizontal sensing signals (DSN) is completed and stored in the memory 712, the second controller 720 After setting the value of the memory state flag (Mem) to 0 (step S33), the value of the unstabilized state flag (UNS) is read to determine whether or not the sensing signal is within the appropriate range (step S34). ). Thus, since the value of the memory status flag (Mem) is set to 0 in step S33, new vertical and horizontal sensing data can be stored in the memory 712 by the data classification unit 711.

  If the value of the unstabilized state flag (UNS) is 1, and it is determined that the sensing signal does not exist within the appropriate range, the reset voltage (Vr) and the like maintain a proper magnitude. The second control unit 720 determines whether or not the contact state flag (TE) is 1 (step S301), and determines whether or not the contact of the sensing unit (SU) has occurred.

  When the contact state flag (TE) is 1, since the contact state check unit 713 determines that contact has occurred in the sensing unit (SU), the second control unit 720 is stored in the memory 750. The contact position is determined by determining again whether or not the sensing unit (SU) is in contact with the vertical and horizontal detection signals (step S302), and the contact information (INF) corresponding to the actual presence or absence of the contact position is generated. (Step S303).

  When the state of the contact information (INF) is 1 indicating that no contact occurs (step S304), the second control unit 720 does not need to operate, so the value of the wake-up flag (WU) is set to 0. (Step S38) After showing the inactive state, the power is turned off and the power saving state is entered (step S39). In this way, unnecessary power consumption in the second control unit 720 is prevented.

  Note that if the state of the contact information (INF) is 0 indicating that a contact has occurred in step S304, the second control unit 720 is continuously maintained in the operating state, so that the standby state (step The process proceeds to S31), and the value of the memory status flag (Mem) is determined (step S32).

  If the value of the unstabilized state flag (UNS) is 0 in step S34, the second controller 720 determines whether the sensing signal is within an appropriate range based on the sensing signal stored in the memory 750. Judgment is made (step S35, step S36).

  If the sensing signal is within the proper range, the second controller 720 does not need to operate. Therefore, after setting the value of the wake-up flag (WU) to 0 (step S38), the power is shut off and the power-saving state is set. (Step S39). In this way, unnecessary power consumption in the second control unit 720 is prevented.

  If the sensing signal does not exist within the appropriate range in step S36, the second control unit 720 outputs a control signal for adjusting the magnitude of the reset voltage (Vr) to the outside via the interface unit 760. (Step S37). As a result, the magnitude of the reset voltage (Vr) is adjusted through an external voltage generator (not shown), etc., and the output level of the sensing signal can be properly determined whether or not the sensing unit (SU) is in contact. To exist within. At this time, the magnitude of adjustment of the reset voltage (Vr) can be determined based on the magnitude of the sensing signal output when the sensing unit (SU) is not in contact.

  As described above, the operation of the second control unit, which consumes a large amount of power, exists as a shutdown state in which the power supply is cut off, except during the operation of adjusting the appropriate range of the sensing signal and when determining the presence / absence of contact and the contact position. Even if an ARM processor that generates about 40 mW of power is used for the second controller 720, the power consumption can be greatly reduced.

Next, the operation states of the first and second control units 710 and 720 will be described with reference to FIG.
In FIG. 9, S indicates the timing when the data classification unit 711 operates, H indicates the timing when the first control unit 710 operates, and A indicates the timing when the second control unit 720 operates. T indicates the timing when the interface unit 760 operates.
As shown in FIG. 9, the value of the memory status flag (Mem) becomes 1 once every frame, and the horizontal and vertical sensing signals corresponding to the memory 712 are stored.

  Since the value of the unstabilized state flag (UNS) is 1 at the initial stage of operation, the second controller 720 needs to be turned on in order to control the stabilization operation of the sensing signal, and the wake-up flag (WU) The value is also 1. Therefore, the second control unit 720 changes the value of the wake-up flag (WU) to 0 in order to switch its operation state to the power saving state after performing the stabilization operation of the sensing signal, and performs such second control. After the operation of the unit 720 is completed, the stable state determination unit 714 of the first control unit 710 changes the value of the unstabilized state flag (UNS) to 0. At this time, the first control unit 710 performs only the vertical and horizontal detection signal classification operations by the data classification unit 711.

  Next, when the value of the contact state flag (TE) is 1, the second controller 720 needs to be turned on in order to determine the presence / absence of contact and the contact position, and the value of the wake-up flag (WU) is also 1 Therefore, the second controller 720 changes the value of the wake-up flag (WU) to 0 in order to switch its own operation state to the power saving state after performing the operation of determining the presence / absence of contact and the contact position. When the contact section (TT) exists in this section, that is, when the contact information (INF) becomes 0, the second controller 720 changes the signal state of the contact information (INF) during the contact section (TT). 0 indicates that contact has occurred. After the operation of the second control unit 720 is completed, the contact state check unit 713 of the first control unit 710 changes the value of the contact state flag (TE) to 0.

  In the embodiment of the present invention, the sensing unit using the variable capacitor and the reference capacitor as the sensing unit has been described as an example. However, the present invention is not limited to this, and other types of sensing elements can be applied. . That is, the common electrode of the common electrode panel and the sensing data line of the thin film transistor array panel have two terminals, and at least one of the two terminals protrudes, and the two terminals are physically and electrically contacted by the user. It is also possible to use a pressure sensing unit that outputs a common voltage as a sensing data signal, an optical sensor whose output signal changes depending on the intensity of light, and the like. The present invention is also applicable to a display device having two or more types of sensing units.

  In the embodiments of the present invention, the liquid crystal display device has been described as the display device. However, the present invention is not limited to this, and the present invention is also applicable to a flat display device such as a plasma display device or an organic light emitting display device. .

  The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto, and various modifications and variations of those skilled in the art using the basic concept of the present invention defined in the claims. Improvements are also within the scope of the present invention.

It is the block diagram which showed the liquid crystal display device by one Embodiment of this invention from the viewpoint of the pixel. 1 is an equivalent circuit diagram for one pixel of a liquid crystal display device according to an exemplary embodiment of the present invention. 1 is a block diagram illustrating a liquid crystal display device according to an embodiment of the present invention from the perspective of a sensing unit. FIG. 3 is an equivalent circuit diagram for one sensing unit of the liquid crystal display according to an exemplary embodiment of the present invention. 1 is a schematic view of a liquid crystal display device according to an embodiment of the present invention. FIG. 6 is an equivalent circuit diagram of a plurality of sensing units connected to one sensing data line in the liquid crystal display device according to the embodiment of the present invention. It is a block diagram of the contact judgment part by one Embodiment of this invention. It is a flowchart which shows operation | movement of the contact judgment part shown in FIG. FIG. 8 is a timing diagram illustrating an operation of the contact determination unit illustrated in FIG. 7.

Explanation of symbols

3 Liquid Crystal Layer 100 Thin Film Transistor Display Panel 191 Pixel Electrode 200 Common Electrode Display Panel 230 Color Filter 270 Common Electrode 300 Liquid Crystal Display Panel Assembly 400 Image Scanning Section 500 Image Data Drive Section 550 Grayscale Voltage Generation Section 600 Signal Control Section 610 Single Chip 620 FPC board 700 contact determination unit 710 first control unit 711 data classification unit 712, 740, 750 memory 713 contact state check unit 714 stable state determination unit 720 second control unit 730 register unit 760 interface unit 800 sensing signal processing unit 810 amplification Part

Claims (19)

A display board;
A plurality of pixels formed on the display panel;
A plurality of sensing units formed on the display board and generating sensing signals based on contact with the display board;
A sensing signal processing unit that receives the sensing signal and performs predetermined signal processing to generate sensing data;
A first control unit for determining whether the sensing unit is touched based on sensing data from the sensing signal processing unit and whether the sensing signal is within an appropriate range; and the sensing based on the sensing data. A contact determination unit including a second control unit that determines presence / absence of contact of the unit and a contact position and controls the detection signal to be within an appropriate range.   The display device according to claim 1, wherein the second control unit is configured using an ARM (advanced RISC machine) processor.   The display device according to claim 1, wherein the first control unit includes hard wire logic. The first controller is
A data classifying unit for classifying the sensing data into vertical and horizontal sensing signals;
A memory unit storing the classified vertical and horizontal sensing data;
A contact state check unit that determines presence / absence of contact of the sensing unit based on a longitudinal sensing signal from the memory unit;
The display device according to claim 3, further comprising: a stable state determination unit that determines whether the detection signal belongs to an appropriate range based on the detection signal from the memory unit.   The display device according to claim 4, wherein the contact determination unit further includes a register unit that stores a plurality of flag values. The plurality of flags are:
A memory status flag indicating that the horizontal and vertical sensing signals are all stored in the memory unit;
A wake-up flag for controlling the presence or absence of the operation of the second control unit;
An unstabilized state flag indicating whether the sensing signal belongs to an appropriate range;
The display device according to claim 5, further comprising a contact state flag indicating whether or not contact has occurred in the sensing unit.   The wake-up flag has a value of an active state when a contact is generated in the sensing unit by checking the contact state or when the sensing signal is not within an appropriate range by the stable state determining unit. The display device according to claim 6.   When the wake-up flag is in an active state, the second control unit determines whether the sensing unit is in contact with the sensing unit based on the sensing data, and determines whether the sensing signal is within an appropriate range. The display device according to claim 7, wherein the display device is controlled to belong.   The display device according to claim 6, wherein the non-stabilized state flag has an active state value when the stable signal is not in an appropriate range by the stable state determination unit.   The display device of claim 9, wherein the non-stabilized state flag has an active state value after an enable signal is applied to the contact determination unit and power is supplied.   The display device according to claim 6, wherein the contact state flag has an active state value when it is determined by the contact state check that a contact has occurred in the sensing unit.   The display device of claim 6, wherein the memory status flag has an active state value when the horizontal and vertical data are all stored in the memory unit by the data classification unit.   The display device according to claim 1, wherein the contact determination unit further includes an interface unit.   The display device according to claim 13, wherein the interface unit is an SPI (Serial Peripheral Interface).   The each of the plurality of sensing units includes a variable capacitor whose capacitance is changed by an external pressure, and a reference capacitor having a predetermined capacitance. Display device. A method for determining presence / absence of contact and a contact position based on sensing signals generated by a plurality of sensing units by contact with a display panel, and controlling a contact determination unit including first and second control units,
It is determined whether an enable signal is externally applied, and when the enable signal is applied, an initialization step of supplying power for the operation of the contact determination unit;
After classifying the sensing signals and storing them in the memory, it is determined whether or not the sensing unit is in contact and whether the sensing signals are within an appropriate range based on the sensing signals, and the wake-up flag is activated. Controlling the first control unit to
When the value of the wake-up flag is in an active state, a second control unit that performs a stabilizing operation for causing the sensing signal to be within an appropriate range and an operation for determining whether or not the sensing unit is in contact and a contact position. And a control step for controlling the contact determination unit.   The initialization process may further include a step of activating values of the wake-up flag and an unstabilized state flag so that a stabilization operation is performed by the second controller. Control method of the contact judgment part as described in 2. The control step of the first control unit includes:
Classifying the sensing signals into vertical and horizontal sensing signals, storing them in a memory, and switching the value of a memory status flag to an active state after the storage is completed;
When the wake-up flag is in an active state, transitioning to the operation of the second controller;
Determining whether the sensing signal is within a proper range if the wake-up flag is not active;
Determining whether contact has occurred in the sensing unit when the sensing signal is within an appropriate range; and
If no contact occurs in the sensing unit, performing a classification operation of the sensing signal;
When contact occurs in the sensing unit, switching the wake-up flag and the contact state flag to an active state;
The method according to claim 17, further comprising switching the wakeup flag and the unstabilized state flag to an active state when the sensing signal is not within an appropriate range. The control step of the second control unit includes:
Determining whether the memory status flag is active;
If the memory state flag is active, determining whether the unstabilized state flag is active;
If the non-stabilized state flag is not in an active state, it is determined whether or not the sensing signal is within an appropriate range after the memory state flag is inactivated, and the sensing signal is within the appropriate range. If not, outputting a control signal for changing the level of the sensing signal;
If the sensing signal is within an appropriate range, the wake-up flag is deactivated and the power is shut off; and
If the unstabilized state flag is active, determining whether the contact state flag is active;
If the contact flag is not active, the wake-up flag is deactivated and the power is shut off;
When the contact state flag is in an active state, determining the presence / absence and contact position of the sensing unit and generating contact information of the contact state;
When a contact occurs in the sensing unit, the process proceeds to determining whether the memory status flag is active;
The method of claim 18, further comprising shutting off the power by setting the wake-up flag in an inactive state when no contact occurs in the sensing unit.

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